James Hart Wyld was born in Pompton Lakes, New Jersey in 1913. He received a Bachelor of Science degree in Mechanical Engineering from Princeton University in 1935. In 1931, he became a member of the American Interplanetary Society, later known as the American Rocket Society or ARS. Established in 1930, the ARS was the first private group to build rockets in the United States. Wyld and other members of the ARS conducted static tests of rockets and rocket engines throughout the 1930's.

In 1936, James Wyld developed the idea of letting rocket fuel circulate around the rocket nozzle using a double wall configuration as a means of producing more powerful rocket engines. He first reported this innovation in the April 1938 issue of the American Rocket Society Journal, Astronautics.

Wyld's "self-cooled tubular regenerative rocket motor," was first tested on December 10, 1938, at New Rochelle, New York. It produced 90 pounds of thrust for thirteen seconds, and its simple steel chamber and nozzle did not burn out. The static test was cut short because the ARS could not afford sufficient amounts of liquid oxygen, but the test was successful. Engines tested by the ARS were primarily intended for JATO (Jet Assisted Take Off) use by aircraft.

The ARS continued to improve on Wyld's original design, and by July 1941, three successful tests of his liquid fuel rocket motor were made, producing an average thrust of 125 pounds. These tests were repeated for the U.S. Navy in November 1941, winning Wyld and his associates a contract to build more rocket engines. On December 16, 1941, Wyld and four other ARS members formed Reaction Motors, Inc. (RMI), the first commercial rocket company in the United States to continue development of his engine design. James H. Wyld was the company's secretary and director of research.

During World War II, Wyld's rocket work was integrated into the American military effort. After meeting its initial Navy contract for a JATO engine with 1,000 pounds of force in 1942, RMI continued to improve on his design, and by 1943, Wyld and his co-workers delivered a JATO engine to the Navy that could produce 3,400 pounds of thrust. RMI's wartime testing was initially done in Franklin Lakes, New Jersey at a facility designed primarily by Wyld, until 1943, when tests were moved to a more remote location in Pompton Plains, New Jersey.

James H. Wyld died in 1953 at the age of forty-one. His concept of a regeneratively cooled engine forms the basis for all modern liquid-propellant rocket motors, and his 1942 breakthrough, the "Wyld Regeneratively-Cooled Rocket Motor, Serial Number 2" is on display at the National Air and Space Museum at the Smithsonian Institution in Washington, D.C. Since 1948, the American Institute of Aeronautics and Astronomics honored Wyld through its James H. Wyld Award and The Propulsion Award, which were combined in 1964 as the James H. Wyld Propulsion Award. In 1975, the name was again modified to the Wyld Propulsion Award, an honor still presented for outstanding achievement in the development or application of rocket propulsion systems. The Wyld Crater on the far side of the Moon is also named for him.